TEQUESTA, Fla. (AP) - Crews pushed the limits of an ever-expanding search zone Wednesday for two teens missing at sea and potentially nearing the boundaries of human survival.

The Coast Guard’s relentless hunt for the 14-year-old fishermen, Perry Cohen and Austin Stephanos, persisted for a sixth day as questions grew about how long it could go. Decision-makers were juggling a mix of “art and science,” Chief Petty Officer Ryan Doss said, trying to balance the knowledge of how long people can survive adrift with the unknowns on whether the boys had flotation devices and drinking water and what their physical condition is.

Still, authorities insisted their search would continue throughout the day.

“There’s been a lot of rumors that the search has been suspended. I just want to refute that,” Capt. Mark Fedor said, speaking on the street where both boys live. “The search has not been suspended. It is still active and open.”

Earlier Wednesday, a U.S. official in Washington had said the Coast Guard was suspending the search.

Fedor was part of a Coast Guard contingent that met with the boys’ families for an hour Wednesday afternoon. Afterward, he declined to elaborate on the search or to answer reporters’ questions, but even a day earlier he acknowledged that with each passing hour, the prospects were direr.

The saga of the two boys from Tequesta, Florida, began Friday. Their parents believed their fishing outing would take them to a local river and waterway, as was the rule in previous solo trips, not the deep waters of the Atlantic. A line of summer storms moved through the area that afternoon, and when the teens didn’t return on time, the Coast Guard was alerted and began their day-and-night search.

The Coast Guard has covered a mammoth search area stretching nearly 40,000 square nautical miles, from the waters off South Florida up through South Carolina. It has proven a frustrating ordeal, with no new clues since the teens’ capsized boat was located Sunday. Sightings of floating objects occasionally spurred hope before being found irrelevant.

Dr. Claude Piantadosi, a Duke University medical professor who authored “The Biology of Human Survival: Life and Death in Extreme Environments,” said finding individuals outside of a boat, simply bobbing in the water, is intensely difficult. The former Navy officer said sailors lost at sea might run an orange streamer 30 to 40 feet behind them to aid being located by air.

“Single people in the ocean are the hardest to pick up,” he said.

Piantadosi, an avid boater and diver, has frequently visited the Atlantic waters where the teens disappeared, and says they are remarkably empty expanses, largely free of anything the boys might be able to grab unto.

“There’s just not that much debris out there,” he said. “Occasionally you’ll find a log or buoy, something like that drifting along, but not very often.”

But the lengthening interval since the boys disappeared does not dispel all hope for them.

In 2005, two South Carolina teens were swept out to sea on their small sailboat during a storm. After searching for them for several days, the Coast Guard and state officials began referring to their effort as a recovery operation instead of a rescue.

Yet the teens were found alive after almost a week at sea. A key difference from the Florida teens, though: They were still aboard their boat.

Each year, Florida waters swallow a small number of boaters who venture out and never return. In 2013, when Florida had 56 boating fatalities, it also had nine missing boaters who were never found and are presumed dead, according to the state Fish and Wildlife Conservation Commission. Last year, there were 64 fatalities and six missing boaters.

The commission could not break down how many of these accidents happened in the ocean, the Gulf of Mexico or on a lake or river.

Dr. Raj Dasgupta, a critical care doctor at the University of Southern California, said the boys’ experience in the open water may be far different from what some might expect.

“They’re usually not going to be found eaten by sharks like some movies would have you believe. They’re going to have fatigue and muscle cramps and dehydration,” he said. “It’s the worst oxymoron in the world: You’re surrounded by water and there’s no water.”

The Washington Times Comment Policy

The Washington Times is switching its third-party commenting system from Disqus to Spot.IM. You will need to either create an account with Spot.im or if you wish to use your Disqus account look under the Conversation for the link "Have a Disqus Account?". Please read our Comment Policy before commenting.